Commercial cathode material (LiCoO2) was modified by coating with a thin layer of SrO/Li2O/La2O3/Ta2O5/TiO2 for improving its performance in lithium ion battery. The morphology and structure of the modified cathode material were characterized by scanning elec-tron microscopy (SEM) and X-ray diffraction (XRD). The performance including cycling stability, diffusion coefficient under different volt-age, C-rate discharge of the batteries with this modified cathode material was examined. The results showed that the battery with the coated cathode material could discharge at a large current density, and it possessed a stable cycle performance in the range from 3.0 V to 4.2 V. It was explained that the rate of Li ion diffusion increased in the batteries using SrO/Li2O/La2O3/Ta2O5/TiO2-coated LiCoO2 as the cathode and the coated layer could act as a fast ion conductor (Sr0.5La0.05Li0.35Ti0.5Ta0.5O3) and as a protecting shell to prevent LiCoO2 particles from be-ing attacked by the acidic electrolyte.